Final answer:
Lenz's law is used to predict the direction of induced current in a circuit when there is a change in magnetic flux, and it states that the induced current will create a magnetic field that opposes the change. The right-hand rule helps visualize the direction of current and magnetic fields. This principle allows us to determine the behavior of circuits in changing magnetic environments, such as when an electromagnet is activated near a wire loop.
Step-by-step explanation:
Lenz's law is used to determine the direction of induced electromotive force (emf) and current when there is a change in magnetic flux. According to Lenz's law, the direction of the induced current in a circuit is such that the magnetic field created by the induced current opposes the change in the original magnetic flux. To visualize this, one can use the right-hand rule where the thumb represents the direction of the current, and the curled fingers show the direction of the magnetic field generated by the current.
When an electromagnet is activated near a wire loop, it creates a changing magnetic field, which induces an emf in the loop. If the magnetic field through the loop increases, the induced current will flow in a direction that creates a magnetic field opposing the increase. Conversely, if the magnetic field decreases, the induced current will flow in a direction that tries to maintain the existing magnetic field. Using the right-hand rule, we can determine the actual direction of the current based on the direction of the magnetic field changes.
Furthermore, by combining Faraday's law with Lenz's law, one can quantify the induced emf in a coil or solenoid. After finding the emf, Ohm's law, ε = IR, can be applied to calculate the current, considering Lenz's law to ensure the direction of the current produces a magnetic field that opposes the initial change.